Device for measuring or checking a transverse dimension in a piece of indefinite length



July 17, 1951 M. MENNESSON 2,550,833

- DEVICE FOR MEASURING OR CHECKING A TRANSVERSE DIMENSION IN A PIECE OFINDEFINITE LENGTH 3 Sheets-Sheet 1 Filed May 15. 1949 llW/flV 70/?M42424 Mam 9504 July 17, 1951 4 M. MENNESSQN 2,560,383

DEVICE FOR MEASURING OR CHECKING A TRANSVERSE DIMENSION IN A PIECE OFINDEFINITE LENGTH Filed May 13, 1949 5 Sheets-Sheet 2 y' 1951 M.MENNESSON DEVICE FOR MEASURING OR CHECKING A TRANSVERSE DIMENSION IN APIECE OF INDEF'INITE LENGTH a Sheets-She et 5 Filed May 13, 1949 JWNY Nmw@m S. T N m J w W L I. m R n I .BY

Patented July 17, 1951 TRANSVE-RSE DIMENSION IN A PIECE OF INDEFINITJELENGTH Marcel Mennesson, 'Neuilly-sur-Seing France, assignor to Societe'dApplications et de Constructions pour Materiel Automobile, (S. A. C. M.A.) S. A. R. L., Neuill-y-sur-Seine, France, a society of FranceApplication-.May is, 1949, Serial No. 93,174 In France June 26, 1948 4Claims.

The present invention relates to devices for measuring or checking atransverse dimensionin a piece of indefinite length, for instancethe-"thickness or the cross section of a wick or of a' wire, of atextile material or a metal respectively, which passes in a continuousmanner and in the longitudinal direction, through a measurementapparatus.

The chief object of my invention is to provide a device of this kindwhich permits of obtaining quickly and by mere reading on a graduatedscale, the mean value of the dimension to be measured,v its variationsmore or less with respect to' its mean value or again" the extrememaximums and= minimums of the curve representing the variations of thedimension measured at different points of the length of the" piece;

Measurement of these variations'may be"performed, for instance, by'means of a pneumatic micrometer of the kind described in the U. S.Patent No; 1,985,576, but it can also be effected through othermeasurement apparatus, of the hydraulic, electric, mechanical or othertypes.

The invention consists chiefly in subjecting the indicating means(manometriccolumn; fiuidflow, pointer) of the measurement apparatus thatis used to the action of means capable of damping the displacements ofsaid indicatingflmeans in at least one direction, damping being obtainedthrough the intervention of a fiuid' which passes through at least onesuitably dimensioned throttled passage and owing to a relative movementtaking place between saidfluid and the piece in which said throttledpassage is provided.

Preferred embodiments of the present invention will be hereinafterdescribed with reference to the accompanying drawings, given merely byway of example and in which:

Figs. 1 to 3 show, in diagrammatic vertical section, respectively,.threedifferent embodiments of the invention;

Fig. 4 shows, in the form of a diagram, the variations that may occur inthe dimensions of the cross section of a thread of a textile material.

For the embodiments shown by Figs. 1 and 2, it has been assumed that themeasurements are made by means of a pneumatic micromeasurement apparatusanalogous to those described in the above mentioned U'. S. patent.

This apparatus essentially includes a tank I, containing a liquid suchas water and open to the atmosphere. In this liquid is immersed a tube 2in communication with a conduit 3 into which air is admittedunderany'suitable pressure. This conduit is provided with an adjustmentcock 4 and a calibrated orifice 5' and it leads to a hollow box 6 in theopposite walls of which are provided two circular and coaxial holes 7aand 7b the section of which is such that it permits the passage;withoutv tight contact, of the wick '8" (or other part) the transversedimensions of which are to be measured, which wick is driven by meansnot illustrated. in a continuous manner through orifices la and 1b.;These means are constituted, forinstance', as indicated in" the U. S;Patents No. 1,971,271 and No. 2,026,187. Tank I and tube 2 form togethera pressure regulating system owing to' which the air pressure in conduit3" is kept at a constant mean value equal to the height H (H grammes, ifthe liquid contained in tank i1 is water) over which tube .2 is immersedin the liquid. The excess of air escapes from thel owe'r end of tube 2'and ascends, in thef'or'r'n of bubbles tothe surface of the'liquid. v

Calibrated orifice 5' opens into a chamber 9 which belongs to conduit 3and with which is connected a pressure gauge is which measures thepressure existing in the portion of conduit 3 between orifice 5 and box6. It is known'that thispressure varies in accordance with the"clear-'an'c'e between the edges of orifices la and F b and the periphery ofWick- 8, which permits of deducing' the value of the dimension to bemeasured from the'value of the'pressure' indicated by pressure'gauge Iton a suitable scale.

,Advantageously, pressure gauge Ml is constituted by a tube connected tothe lower portion of tank I and opening intochamber 5;.

If thetextile'wick 8 is caused to pass at a cer tain rate through theorifices la and lb of box 6 and if the values read on the pressure gaugeare plotted on a diagram (Fig. 4)' where abscissae correspond to thelengths L of the wickand ordinates to theva'lues S of the crosssections-there of, the Values of these sections being indicated belowaxis 0L and the negative ordinate increas m when the section increases,I- obtain a curve A representing the variations of thissection. Fig. 4shows that this curveincludes groups of sawteeth the amplitudes of whichare very different and the distances of whichfrom axis 6L are variable;It is thus diflicult to be able to ascertain the approximative meanvalue of the cross section;

The present invention permits of remedying this drawback by dampingthese variations in such manner that at least those of the secondordernolonger infiuence'the pressure gauge reading', wherebythis-reading becomes-more stable at 3 a limit level about which onlyvery small variations are registered, which variations can, in firstapproximation and for usual curves, be com sidered as being equal tozero.

This limit level therefore gives the mean section of the textile wickthat is being considered and may be represented by a substantiallyhorizontal line B (Fig. 4) the ordinate of which corresponds to the meanvalue of the cross section of the wick or thread that is being measured.Being given this section it is possible to calculate the weight permetre of the wick or to know the numeral of the thread.

In order to obtain this eifect and as shown on Fig. 1, I provide, at thelower end of manometric tube II], a piece II in which is formed athrottled passage I2 and the wick is made to pass through orifices Iaand lb at the same rate as above. As manometric tube ID no longercommunicates with the external portion of "tank I through a largepassage but through a more or less reduced passage I2, liquid can nolonger flow up and down through this tube as easily as before and can nolonger follow in a sufficiently quick and accurate manner the secondaryvariations of pressure,

which not only causes the saw-teeth of curv 4 to disappear but alsoeliminates the undulated shape thereof.

The free level of the liquid then becomes substantially stable at apoint which approximately gives the horizontal line B of Fig. 4.

I can also determine the mean variation more or less of the measurementsmade on a wick or a wire with respect to its mean section which,

on the diagram of Fig. 4, corresponds for instance I to a straight lineC substantially parallel to horizontal line B and which, in the case ofthe determination of a mean variation in less, i nearer to the axis ofabscissae L than line B and at such a distance therefrom that the sum ofthe areas hatched in one direction and limited by curve A between linesB and C is equal to that of the areas hatched in the other direction andlocated beyond line C on the side of axis 0L.

For this purpose I provide, as shown by Fig. 2,

in piece II and parallel to passage I2, a second passage I3 fitted witha check valve, for instance a ball I4 housed in a recess provided inthis piece. This ball is preferably of a density substantially equal tothat of the liquid that is used and a pin I6 prevents it from escapingfrom the recess. In the example shown, ball I4 is moved away from itsseat when it is subjected to the thrust of the liquid from tank Ithrough passage I3, that is to say when the liquid has a tendency toascend through manometric tube III due to a drop of the pressure inconduit 3 on the downstream side of calibrated orifice 5. Liquid cantherefore flow in a relatively easy way through both of the passages I2and I3. On the contrary, upon a rise of this pressure, ball I4 isapplied upon its seat and liquid can move down in tube III only throughpassage I2, whereby the free level of the manometric column getsstabilized at a level higher than that of the mean value, with verysmall oscillations, which can be considered as negligible. The valuethat is obtained is then represented by a straight line parallel tohorizontal line B and if the dimension of passages I2 and I3 aresuitably chosen this straight line can come to coincide with line C.

By giving passage I2 a very small diameter and passage I3 a relativelylarger diameter, it is possible to obtain a curve (not shown) themaximum point, or points, of which correspond to the points 4 where thewick or thread i of the smallest section and where it therefore risksbreaking.

By arranging the check valve I4 so that it opens in the opposeddirection (toward the tank), I obtain an indication relating to theareas of curve A located below horizontal line B on Fig. 4,

' which permits, for instance, of determining a line D symmetrical of C,representing the amount of material used in excess for the manufactureof a'wick or thread supposed to be of a given size. Likewise, themaximums or minimums of curve A can easily be determined by givingsuitable dimensions to passages I2 and I3.

The lowest minimum and the highest maximum can be obtained by stoppingpassage I2 and leaving only passage I3, with its check valve I4, theopening of which then takes place in the suitable direction, as aboveexplained.

Passages I2 and I3 might quite as well be provided at the upper part ofmanometric tube II'I soas thus to obtain damping of the variations of thair pressure acting upon the manometric column.

Fig. 3 shows an application of the invention to a mechanical measurementapparatus.

In a casing II, there is mounted a rigid pointer I8, rotatable about apivot I9 and the fre end of which runs along a circular graduated dial20. Beyond pivot I9, the pointer carries a perfectly elastic arm 2I thefree end of which is hinged, about an axis 22, to a contact member 23subjected to the action of a return spring 24. This contact member iintended to bear upon the piece 23 to be measured. At an intermediatepoint 26, pointer I8 is connected, through a link 21, with a piston 28housed in a cylinder 29, which contains a liquid (oil for instance) andfiuidtightness of which, at the point where link 21 passes, is ensuredfor instance by suitable pack-' check valve), or a passage I3a with acheck valve' I la opening in one direction or the other, or again twopassages analogous to I21; and I3a, and the same effects as abovementioned are obtained. The only difference is that in these precedingexamples, the fluid is moving and piece II remain stationary whereas, inthis case, piston 28 moves and the fluid merely passes from one chamberof cylinder 29 to the other.

A device analogous to that of Fig. 3 may be used with a mechanicalpressure gauge, for instance one of the Bourdon type.

In a general manner, while I have, in the above description, disclosedwhat I deem to be practical and efficient embodiments of my invention,it should be well understood that I do not wish to be limited thereto asthere might be changes made in the arrangement, disposition and form ofthe parts without departing from the principle of the present inventionas comprehended within the scope of the accompanying claims.

What I claim is:

1. A device for measuring or checking a transverse dimension of a pieceof indefinite length which comprises, in combination, a pneumaticmeasurement apparatus including a closed chamber having an inlet and atleast one outlet aperture, said outlet aperture being shaped anddimensioned to correspond with a predetermined play to said dimension ofsaid piece so as to permit the continuous passage of said piece throughsaid outlet aperture, means for feeding a gas under pressure tothe inletof said chambar, including a calibrated orifice, liquid tank meansarranged to cooperate with said gas feeding means for keeping at aconstant value the pressure of said gas on the upstream side of saidcalibrated orifice, a liquid column pressure gauge for measuring thepressure of said gas on the downstream side of said orifice, and a partprovided with a passage of restricted section interposed between thebottom of said pressure gauge and said tank means below the liquid leveltherein so as to slow down the displacements of said liquid column incommunication with said tank means through said passage, said part beingfurther provided with a second passage extending therethrough, and acheck valve in said second mentioned passage.

2. A device according to claim 1 in which said check valve consists of aball of a material the density of which is at least substantially equalto that of the liquid.

3. A device according to claim 1 in which the first mentioned passage ismade of a relatively REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,854,094 Aschenbach Apr. 12,1932 2,019,066 Balsiger Oct. 29, 1935 2,077,525 Mennesson Apr. 20, 1937FOREIGN PATENTS Number Country Date 402,008 Great Britain Nov. 23, 1933

